After visiting Juarez in July, Schmidt suggested Google’s intelligence capabilities could be used to facilitate information-sharing about cartel activity among police and citizens. A great idea—and one that Mario Romero and Jose Antonio Bolio, two friends from Merida, Yucatan, had already started implementing with their free app, Retio.

The application allows citizens to report shootings, murders and assaults as well as broken traffic lights, road blocks (illicit and otherwise), abandoned cars, police abuse and instances of corruption via Twitter. Contributors use the handle for the corresponding city, e.g. @RetioDF for Mexico, D.F., and tweet a description of the problem, sometimes with photo evidence.

An automatic system categorizes the report by type of issue, deletes spam and retweets from the feed. While anyone with a Twitter account can contribute information and access the website and search their city or state, only iPhone and iPad users can download the app. Users search by type of incident or by looking at a map – reports link to the GPS location when possible. Retio users can also map each others’ entries as posts almost always include cross streets.

“The original goal was to organize and optimize Twitter to avoid different problematic situations that people face every day in Mexican cities,” Romero says. “Users in different cities started using hashtags to inform themselves of these type of situations, but it wasn’t an ideal solution – our plan was to build a better tool to resolve this and we’ve been able to do that. But we’re still not done.”

Romero, a 29-year-old who studied industrial engineering, says he and Bolio, 24, started working on the project in January 2011. Retio launched online in Merida in July then expanded to Mexico City, Monterrey and Guadalajara, Mexico’s three largest cities, by August. By February 2012 they launched the iPhone app and extended coverage to all states.

As of Monday morning, Retio’s Mexico City feed had nearly 62,000 tweets and more than 6,000 followers. Monterrey showed a similar ratio, but Ciudad Juarez, whose Twitter account was created in July 2012, only had two tweets and 14 followers.

“We’ve seen the same pattern repeated in several cities,” Romero says. “Few users at first, but an accelerating growth as more users join when a ‘viral’ effect is produced.”

In Mexico, citizens have used social media to warn others in their community about shootings, muggings and areas to avoid for years. Retio adds a forum for reporting corruption and misbehavior by authorities.

“We also believe it is important for authorities to know they are being watched by the citizenry at all times and behave accordingly,” reads the site’s FAQ. Retio’s creators say the newfound transparency will help inhibit extortion, arbitrary detentions and other abuses of power.

But unlike Blog del Narco, Retio makes no promises of anonymity to its users. The co-founders don’t hide behind a cloak of firewalls and are listed by name and photo, along with friends who often help out with the site and app.

“We haven’t received any threats, although the reaction of some authorities has not been ideal,” Romero says, adding that both the police and municipal officials responsible for fixing potholes and keeping streetlights working are none too pleased about Retio.

“The system forces an instant transparency as far as attention to citizens, and that’s something they’re not used to yet,” he says. “As far as the criminals, especially narcos, I think they would probably be more worried about other types of reports, like journalistic investigations that expose them and their connections, than about citizens alerting each other about shootings and risky situations.”

Currently, Twitter feeds are available for every state and for many cities within each state. Romero says the next step will be to expand to other countries, which he says they will begin before the year is up.

“We believe that even though the distribution of the types of problems is different among different cities, even among cities in Mexico, the advantages offered by the collaboration and coordination between citizens are universal.”

Priscila Mosqueda is a contributing writer at the Observer, where she previously interned. She grew up in San Antonio and graduated with a bachelor's in journalism from the University of Texas at Austin in 2012. Her work has appeared in InsideClimate News, The Center for Public Integrity, The Daily Beast, and various Central Texas outlets.